1. Field of the Invention
The invention relates generally to arc lamps and more specifically to arc lamps useful as soldering tools and in fiber optic bundle illumination applications for medical endoscopes, instrumentation and projection.
2. Description of the Prior Art
Short arc lamps provide intense point sources of light that allow light collection in reflectors for applications in medical endoscopes, instrumentation and projection. Short arc lamps are used in industrial endoscopes for the inspection of jet engine interiors.
Conventional lasers have been used to solder, weld and cut metals. However, lasers powerful enough to do so are also powerful enough to cause serious injury to human operators. Such injury can easily happen when a stray laser beam reflects off the workpiece. It is therefore customary for operators to wear special glasses and shop coats for their protection.
Ordinary light is non-coherent and must be focused to form tight spots of light to have the intensity needed to solder or weld metal. With such a spot of light, there is little danger of injury from misdirected or reflected light, because the non-coherent light will simply scatter in low energy rays.
FIGS. 1A and 1B represent a prior art soldering device 10, based on a conventional arc lamp 12, that is described in Japanese Patent Application 2-14499, filed Feb. 15, 1992, in the Japanese Patent Office, by Makoto Kobayashi, et al. Arc lamp 12 and an external reflector 14 are used to pipe light down a fiber optic cable 16 to an end fitted with a window 18 and a hood 20 for soldering and light-weight welding. The assembly places the arc lamp 12 including a power supply 22, reflector 14 and one end of the fiber optic cable in a housing that remains stationary. A supply of inert gas (not shown) is needed at a remote unit that comprises the other end of the fiber optic cable 16, the window 18, the hood 20 and an inlet in the hood 24 that allows inert gas to fill the hood 20 to exclude smoke, residue and splatter during soldering or welding of a workpiece 26. Integrated short arc lamps are smaller and less bulky than arc lamp 12 and its non-integrated reflector 14.
FIG. 2 illustrates a typical prior art short arc lamp 30 that comprises an anode 32 and a cathode 34 positioned along the longitudinal axis of a cylindrical body 36 with a sealed concave parabolic cavity 38 that contains xenon gas pressurized to several atmospheres. U.S. Pat. No. 4,633,128, issued Dec. 30, 1986, to Roy D. Roberts, the present inventor, and Robert L. Miner, describes such a short arc lamp in which a copper sleeve member 40 is attached to a wall 42 to conduct heat from wall 42 through to an exterior wall 44 and a metal ring 45 with a heat sink (not shown) and eventually to circulating ambient air. A flat glass window 46 seals in the xenon gas.
The prior art soldering apparatuses that use arc lamps for a heat source are too bulky and expensive because a large reflector is needed for a conventional arc lamp to focus a tight beam down a fiber optics cable. A far less bulky and inexpensive short arc lamp based system is needed in the market.